InsideSurgery Medical Information Blog » Nanomedicine

Researcher Create Prototype Of Artificial Muscle From Nanotube Forests

Editor — Fri, 27 Mar 2009 00:20:36 +0000

Ray Baughman and colleagues at the University of Texas have fashioned an a grouping of carbon nanontubes into an interlocking aerogel pattern that could be the prototype of an artificial muscle. The aerogel “flexes” when stimulated by an electrical charge and can also lengthen to over twice its original length in milliseconds.

The aerogels are made from carbon nanotube forests which have carbon nanotubes identically aligned vertically. Once formed the nanotube aerogels have directional properties. When electrically charged, the aerogels can expand thirty times in the sheet direction but are extremely stiff in the nanotube direction.

This prototype artificial muscle reacts and contracts at a rate 1000 times greater than human muscle and generates a force 30 times greater than human muscle. It is functional over a temperature range from 80 – 1900 K.

Possible future medical uses of this technology include use as human muscle actuators and in robotic prosthetics.

Researchers Build Arthroscopic Nanomicroscope

Editor — Sat, 11 Aug 2007 16:33:44 +0000

Researchers in Switzerland haved modified a scanning force microscope so that it can be used to diagnose the earliest stages of osteoarthritis.

Osteoarthritis is a progressive disease that is characterized by the degradation of articular cartilage. Significant and irreversible damage is usually present by the time symptoms appear in middle age. Current devices used for measuring the biomechanical properties of cartilage are sensitive only down to a resolution of millimeters which is much too large to pick up early lesions.

Scanning force microscopes (SFM) use a fine nanometer scanning tip which can be run over any surface to accurately map surface changes ranging from nanometers to millimeters. It can also detect biomechanical properties of a surface by having the tip pressed into the surface and recording and analyzing the resultant deformation.

Recently, Martin Stolz and colleagues at the Swiss Nanoscience Institute have placed a SFM into a standard arthroscopic cannula to image the human knee in vivo. Previously, the team had studied healthy and diseased tissue ex vivo and found that the collagen fibrils in the osteoarthritic knee that are normally oriented in 3D become clumped in the direction that the knee moves.

Copyright 2007 InsideSurgery.com

Nanoslit Panel Produces Perfect DNA Alignment

Editor — Tue, 03 Jul 2007 00:42:00 +0000

Researchers at the Technical University of Dresden and the Institute of Integrative Nanosciences (both in Germany) have perfected a technique for aligning DNA using nanoslit technology.

A drop of solution containing DNA is placed at one end of panel with channels 2-10 microns long and 100 nm deep. The solution is allowed to move across the panel by capillary action. After approximately 1 minute a buffer is applied to arrest movement. The DNA is then examined and has been found to have spontaneously stretched and perfectly aligned adjacent to the slit wall.

One of the lead developers Madhavi Krishnan reports that the technique will even unravel complicated DNA structural formulations such as loops. He reports that the panels are easily mass-produced and trivial to make.

Copyright 2007 InsideSurgery.com

Gold Nanorods Can Detect Inflammation In Vivo

Editor — Sat, 30 Jun 2007 13:34:26 +0000

Researchers in Michigan are using a technique called photoacoustic imaging to observe inflammed cells being grown in a culture dish. Inflammation is a key physiologic component of diseases such as systemic lupus erythematosus, rheumatoid arthritis, stroke, and heart disease.

Photoacoustic imaging is a process where a laser directed at tissue causes the tissue to heat up and expand. This expansion gives off sound waves which can be measured if the correct equipment is available to measure the sound energy. In addition, the use of certain materials can give better resolution to the recorded and measured sound.

Kang Kim and colleagues at the University of Michigan are using gold nanorods as one of these materials to detect the subtle differences in sound coming off inflammed tissue as opposed to non-inflammed tissue when it is subject to a laser.

His team stimulated endothelial cells from the human umbilical vein to become inflamed and to consequently express a molecule called ICAM-1. They then treated gold nanorods with antibodies to ICAM-1 and mixed them with the inflamed cells and also with endothelial cells that were not inflamed.

After one hour, the cells were rinsed with saline. The inflamed cells that now had the gold nanorods fixed to them had a much louder and distinct sound profile than did the non-inflamed cells.

Kim’s team is beginning experiments in animals to see if the gold nanorods coated with ICAM-1 antibodies will attach to inflamed cells in a living organism.

Copyright 2007 InsideSurgery.com

New Type of Nanoparticle Fights Drug Resistance in Tumors

Editor — Sun, 17 Jun 2007 12:27:41 +0000

One of the most vexing problems for oncologists and disheartening developments for patients is the development of drug resistance by tumor cells. When this occurs, the chemotherapy used by physicians has an initial effect that kills cancer cells and shrinks the tumor size. But, after the treatment course is completed, the remaining cells cause an eventual return of the tumor that is termed a clinical relapse.

This scenario is distressingly common in patients with ovarian cancer and is a reason for the late mortality of this disease. However, a new strategy to combat the mechanism that some cells use to avoid death following chemotherapy has been developed by Mansoor Amiji, PhD and fellow researchers at Northwestern University.

This team, who also collaborated with researchers from the Massachusetts General Hospital, has developed a polymeric nanoparticle that is capable of delivering chemotherapy to ovarian cancer cells using a staged, two drug delivery system. The first drug released is ceramide which knocks out a key early enzyme that cells use to avoid programmed cell death (apoptosis). The second drug loaded onto the nanoparticle and delivered to the cancer cell lacking the key enzyme is paclitaxel, which has traditionally been the first-line drug to fight ovarian cancer.

The Northwestern invesigators showed that the two drug nanoparticle killed 100% of drug-resistant ovarian cancer cells in vitro (growing in culture in the lab).

The full description of the experiment is detailed in the paper Modulation of Intracellular Ceramide Using Polymeric Nanoparticles to Overcome Multidrug Resistance in Cancer. The abstract can be viewed via PubMed.

Copyright 2007 InsideSurgery.com